<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<title></title>
	<style>
		.normal{
			width: 200px;
			height: 200px;
			background: darkred;
		}

		.float{
			width: 200px;
			height: 200px;
			float: left;
			background: chocolate;
			margin-left: 100px;
			margin-top: -20px;
			/*非定位浮动盒子会覆盖常规流块盒是因为z-index排列顺序*/
		}
	</style>
</head>
<body>
	<div class="container">
		<div class="item"></div>
	</div>

	<div class="normal"></div> <!-- 设置一个常规流块盒 -->

	<div class="float"></div>	<!-- 设置一个浮动盒子 -->
</body>
</html>